Dietary diversification/modification strategies to enhance micronutrient content and bioavailability of diets in developing countries

Both cereal staples and household diets can be manipulated to enhance the c ontent of micronutrients and/or alter the levels of absorption modifiers to improve micronutrient bioavailability. Strategies described range from pla nt breeding, use of fertilizers and genetic engineering to changes in food preparation and processing methods at the household level involving soaking , fermentation and germination. The impact of five household strategies des igned to enhance the content and bioavailability of iron, zinc and calcium in a representative daily menu for rural Malawian preschool children has be en calculated using food composition data. In the five strategies, relishes based on small dried fish replaced plant-based relishes, maize-based porri dges prepared with maize flour soaked to reduce its hexa (IP-6)- and penta (IP-5)-inositol phosphate content replaced conventional porridges; and a pu mpkin-leaf relish replaced sweet potato to increase the retinol content of the daily menu. Comparison of the calculated energy, nutrient, and phytate content, and [phytate]:[zinc] molar ratios of the five modified menus compa red with the unmodified menu emphasizes that to ensure that the estimated r equirements for iron and zinc are met, the optimal strategy includes dried fish relish twice daily together with porridges prepared using soaked (or f ermented) maize flour to reduce their hexa- and penta-inositol phosphate co ntent. Implementation of these household strategies has the potential to in crease the bioavailability of iron and zinc in rural Malawian diets from lo w to high.